Phylogenetic relationships of southwestern spiders in Iran utilizing the mitochondrial COI marker

Spiders are recognized for their significant contributions to the ecosystem, serving as generalist predators of insects and various other arthropods. The significant morphological diversity found in spiders complicates their classification. DNA barcoding is regarded as a fundamental instrument in taxonomy due to its accuracy in species identification.In this study, spiders were collected from Kohgiluyeh and Boyer-Ahmad Province. The species were identified using a valid identification key and then compared with submitted sequences in GenBank. Identifiable species were selected for molecular evaluation and phylogenetic analyses using the Maximum Likelihood phylogenetic tree-building algorithm. The study focused on 7 families and 13 species of specimens. The correlation between the identified COI and the sequences deposited in GenBank was distinctly evident and exhibited a strong clustering at both the family and species levels. The analysis revealed that the genera Haplodrassus, Trachyzelotes, Drassodes, Hogna, Xysticus, Steatoda, and Frontinellina formed monophyletic clades, which were supported by high bootstrap values.The findings indicated a significant alignment between morphological classifications and those derived from COI barcode sequences. We successfully identified all selected spider species with complete accuracy via the COI mitochondrial marker. Additionally, the Linyphiidae family exhibited a paraphyletic lineage within the phylogenetic tree, which may be the common ancestor of all spider species.